Average Peak Bloom Date: April 4

2011 Peak Bloom: March 29

2011 Blooming Period: March 26 - April 7.

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Green Color in Buds: 3/7/2011

Florets Visible: 3/9/2011

Extension of Florets: 3/16/2011

Peduncle Elongation: 3/19/2011

Puffy White: 3/22/2011

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Average Peak Bloom Date: April 4

Bloom Watch updated March 29, 2011

The Peak Bloom Date and Blooming Period

The Peak Bloom Date is defined as the day in which 70 percent of the blossoms of the Yoshino Cherry (Prunus x yedoensis) trees are open. The date when the Yoshino cherry blossoms reach peak bloom varies from year to year, depending on weather conditions. Cherry Blossom Festival dates are set based on the average date of blooming (April 4), but nature is not always cooperative. Unseasonably warm and/or cool temperatures have resulted in the Yoshino cherries reaching peak bloom as early as March 15 (1990) and as late as April 18 (1958).

The Blooming Period is defined as the period that starts when 20% of the blossoms are open and ends when the petals fall and the leaves appear. The Blooming period starts several days before the Peak Bloom Date and can last as long as 14 days; however, frost or high temperatures combined with wind and/or rain can shorten this period.

During the Blooming Period, the National Park Service conducts annual Cherry Tree Walks and Bike Tours around the Tidal Basin. These Park Ranger conducted programs present an interpretive look at the historical and cultural influence of the Japanese Flowering Cherry Trees in our Nation's Capital. For information on the dates and times of the walks and bike tours please call (202) 426-6841.

It is nearly impossible to give an accurate forecast much more than 10 days before the Peak Bloom and each year National Park Service Horticulturists monitor 5 stages of bud development and provide a forecast and updates as needed. The following is a comparative record of past bud development in which 70% of the buds reached each stage:

NPS

Green Color in Buds: Late February to Early March

NPS

Florets Visible: March, Average 16-21 days to Peak Bloom.

NPS

Extension of Florets: Average 12-17 days to Peak Bloom.

NPS

Peduncle Elongation:(Frost Critical) Average 6-10 days to Peak Bloom.

NPS

Puffy White: Average 4-6 days to Peak Bloom.

2008 Blooming Period: March 26 - April 11, 2008 17 Days
2009 Blooming Period: March 28 - April 09, 2009 13 Days
2010 Blooming Period: March 27 - April 05, 2010 10 Days